what is hydrocolloids

2. HYDROCOLLOIDS
 Hydrocolloids are polysaccharides of high molecular
weight extracted from plants and algae or produced by
microbial synthesis.
 A hydrocolloid is a suspension of particles in water where
the particles are molecules that bind to water and to one
another
 The term hydrocolloids embraces all the many
polysaccharides that are extracted from plant, seaweeds
and microbial sources, as well as gums derived from plant
exudates, and modified biopolymers made by the chemical
treatment of cellulose

3. COMMONLY USED
 Alginates
 Carrageenans
 Agar
 Guar gum
 Arabic gum
 Carboxymethyl cellulose

4. ADVANTAGES
 Processing aids
 Provide dietary fiber
 Impart specific functional properties or perform a
combination of these roles.
 Guar and xanthan gums, have been used at
7 % and 2 % levels, respectively, in bread to provide
dietary fiber for therapeutic purposes

5. Role of hydrocolloids in
manufacture of baked goods
 In the baking industry, hydrocolloids are of increasing
importance as
 Bread improvers
 They can induce structural changes in the main
components of wheat flour systems along the
breadmaking steps and bread storage
 Hydrocolloids are used either alone or in combination to
achieve specific synergies between their respective
functional properties

6. Role of hydrocolloids in manufacture of
baked goods Contd…
• Hydrocolloids when used in small quantities (<1% (w/w)
in flour) are expected to increase water retention and loaf
volume and to decrease firmness and starch retrogradation
• The highly hydrophilic nature of hydrocolloids also helps
to prevent the growth of ice crystals during frozen storage
of products, and the migration of water from the substrate
to the coating, which improves the freeze/thaw stability

7. Role of hydrocolloids in manufacture of
baked goods Contd…
 The presence of hydrocolloids influenced melting,
gelatinization, fragmentation, and retrogradation
starch processes.
 These effects were shown to affect pasting properties,
dough rheological behavior bread staling

8. Role of hydrocolloids in manufacture of
baked goods Contd…
 There are many possible factors involved in this, the
most important being the molecular structure of
hydrocolloids and/or ionic charges of both starches
and hydrocolloids
 A reduction of pasting temperature was achieved
when 1 % alginate was added implying an earlier
beginning of starch gelatinization and subsequently an
increase in the availability of starch polymers as
amylase substrate for dextrinization during the baking
period

9. Role of hydrocolloids in manufacture of
baked goods Contd…
 Xanthan gum and pectin increased cooking stability
and guar gum and cellulose derivatives increased
viscosity values during cooling while alginate, xanthan
gum and carrageenan showed the opposite effect

10. OTHER USES
 Hydrocolloids have a neutral taste and aroma which
permits a free flavour release of all recipe components
 They provide an unctuous body to fat-reduced
products in which they compensate for the low fat
content with their water-binding ability and
texturising properties
 These compounds have been used as gluten
substitutes in the formulation of gluten – free breads
due to their polymeric structure

12. Arabic gum
 Arabic gum is a water-soluble dietary fiber derived
from the dried gummy exudates of the stems and
branches of Acacia senegal
 Improves
 bread external appearance and its internal
characteristics such as texture, cell wall structure, colour
and softness

13. Karaya gum
 Karaya gum is a natural gum exudate of Sterculia urens,
 It is widely used in food industry as food additive.
 The wider application of this gum due to its unique
features such as high swelling and water retention capacity,
high viscosity properties, inherent nature and abundant
availability
 This hydrocolloid can be used in bakery products for
improve tolerance to variations in water addition and
mixing time.
 Due to its water-binding capacity, it also slows down aging,
extending the shelf-life of baked goods

15. Carrageenan
 Kappa carrageenan is a sulphated polysaccharide
extracted from certain red algae
 Has an ability to improve the specific volume of the
bread due to its interactions with gluten proteins

16. Agar
 Agar is a hydrophilic colloid extracted from seaweeds
of the Rhodopyceae
 Agar gels can hold large amount of soluble solids such
as sugar without allowing crystallization, becoming
opaque, or losing adhesive properties.
 They are used widely in the preparation of bakery
glazes, icings, toppings etc.
 They are also effective in the formulation of good
quality piping jellies for fillings in doughnuts, filled
cakes

17. Alginates
 Alginates are a polyuronic saccharides isolated from
the cell walls of a number of brown seaweed species .T
 They are used to stabilize bakery toppings and icings,
as well as to prevent the sticking of products to
wrapping paper.
 Other bakery applications in which alginates are used
include meringues and fruit or chiffon pie fillings
 Addition of these compounds provides bakery cream
with freeze/thaw stability, reduced syneresis, improves
shelf life and moisture retention in bread and cake
mixes

19. Guar gum
 Guar gum is a galactomannan derived from the seed of
a leguminous plant Cyamopsis tetragonolobus
 Its solutions are highly viscous at low concentrations
and useful in thickening, stabilization and water-
binding applications

20. Guar gum Contd…
 In bakery products, Guar gum is used to improve
mixing and recipe tolerance, to extend the shelf life of
products through moisture retention and to prevent
syneresis in frozen foods and pie fillings
 Delays bread staling by softening effect likely due to a
possible inhibition of the amylopectin retrogradation,
since it preferentially binds to starch.
 It is explained by influence on formation of amylose
network avoiding the spongy matrix creation

21. Locust bean gum
 Locust bean gum is a natural hydrocolloid extracted
from the seeds of carob tree (Ceratonia siliqua L.)
 Its application for bakery purposes results in higher
baked product yields; it improves the final texture and
adds viscosity in dough.
 It is also effective in lowering serum lipids and in
dietary treatment of diabetics

23. Xanthan gum
 Xanthan gum is extracellular polysaccharide secreted
by the bacterium, Xanthomonas campestris
 This hydrocolloid contributes smoothness, air
incorporation and retention, and recipe tolerance to
batters for cakes, muffins, biscuits and bread mixes

24. Xanthan gum Contd…
 At low concentrations provides storage stability and
water binding capacity.
 Its pseudoplastic behavior is important in bakery
products during dough preparation, i.e. pumping,
kneading and moulding.
 It prevents lump formation during kneading and
improves dough homogeneity

25. Xanthan gum Contd…
 It induces cooking and cooling stability in wheat flour
and improves the freeze/thaw stability of starch-
thickened frozen foods .
 It also improves the cohesion of starch granules, thus
providing a structure to these products.
 It is used to increase water binding during baking and
storage and thus prolongs the shelf life of baked goods
and refrigerated dough.

26. Xanthan gum Contd…
 It also increases water absorption and the ability of the
dough to retain gas, increasing the specific volume of
the final bread and the water activity of the crumb
 It can also be used in soft baked goods for the
replacement of egg white content without affecting
appearance and taste.
 It is also used in prepared cake mixes to control
rheology and gas entrainment and to impart high
baking volume.
 Solid particles like nuts are prevented from settling
during baking

27. Gellan gum
 Gellan gum is an anionic deacetylated exocellular
polysaccharide produced by fermentation of
Sphingomonas paucimobilis
 This gum is used in a variety of food that includes
water-based gels, confectionery, jams and
marmalades, pie fillings and puddings, fabricated
foods and dairy products

29. Hydroxypropyl methylcellulose
 Hydroxypropyl methylcellulose is water-soluble fiber which
has been used in food for decades to enhance the
manufacturing process and improve food product qualities
 This compound is obtained by the addition of methyl and
hydroxypropyl groups to the cellulose chain
 The etherification of hydroxyl groups of the cellulose
increases its water solubility and also confers some affinity
for the non-polar phase in doughs.
 Hence, in a multiphase system like bread dough, this
bifunctional behaviour allows the dough to retain its
uniformity and to protect and maintain the emulsion
stability during breadmaking

30. Hydroxypropyl methylcellulose
Contd…
 In breadmaking it improves its quality-loaf volume,
moisture content, crumb texture, and their sensorial
properties
 It is a good antistaling agent for retarding the crumb
hardening
 Its effect is attributed to their water retention capacity,
and a possible inhibition of the amylopectin
retrogradation

31. Carboxymethyl cellulose
 Carboxymethyl cellulose is a cellulose derivative with
carboxymethyl groups bound to some of the hydroxyl
groups present in the glucopyranose monomers that
forms cellulose backbone
 It is used in baked goods mostly to retain moisture, to
improve the body or mounth-feel of the products, to
control sugar and ice crystallization , to protection
against leavening losses in cake mixes, to improving
volume and uniformity of baked products, and to
increase of the shelf life of cereal products

33. Chitosan
 Chitosan (deacetylated chitin), a polycationic biopolymer
is commercially prepared from shellfish-processing waste
and is non-toxic, biodegradable and biocompatible
 It exhibits antibacterial and antifungal activity and has
therefore received attention as a potential food preservative
of natural origin
 The positive effects of chitosan on bread staling was also
determined.
 It increases water migration rate from crumb to crust,
prevents amylose-lipid complexation, and increases
dehydration rate both for starch and gluten

34. Milk proteins
 Whey proteins are primarily used in cereal products to
improve nutritional properties. Whey protein
concentrate is considered to be the most efficient
wheat protein supplement and also increases calcium
content when added to cereal products
 Whey proteins exert negative effects on bread quality,
by depressing loaf volume and increasing crumb
firmness. However, modification of the extent of
protein denaturation by heat treatment or the use of
high hydrostatic pressure can counteract these effects

35. Milk proteins Contd…
 Sodium caseinate, which has excellent surfactant
properties, attributed to the amphiphilic nature of the
protein, is used as an emulsifier, thickener and
foaming agent and is known to increase water
absorption in flour systems.
 It was also demonstrated that this compound was very
effective as an improver in wheat bread prepared by a
straight dough baking process

36. Milk proteins Contd…
 Enrichment of pasta flours with non-denatured whey
protein products results in firmer cooked noodles
which are also more freeze-thaw stable and suitable for
microwave cooking